Broadcaster Alan Jones has denied he had a "bitter hatred" for a prominent Queensland family he is accused of defaming over several years.

Mr Jones is giving a second day of evidence at his defamation trial at the Supreme Court in Brisbane before Justice Peter Flanagan, where he has maintained he was not a liar and was not "careless with the truth".

Mr Jones is being sued by the Wagner family, who claim they were defamed when the broadcaster implied they were responsible for the deaths of 12 people when one of their quarry walls collapsed during the Grantham floods in Queensland's Lockyer Valley in 2011.

Covering nearly one-third of the continent, in deserts with poor soils, humble Australian spinifex grasses contain nano-sized particles that can amp the performance of a range of everyday items, researcher Nasim Amiralian writes.

Former treasurer Wayne Swan says that real private sector wages have grown by just 1 per cent under the Abbott and Turnbull governments, which he says equates to only one year of growth under the previous Labor government.